It is known to make detergent compositions in tablet form by compacting a granular detergent composition. Such tablets offer the convenience to consumers of a pre-measured detergent dosage without the inconvenience and untidiness of measuring a sufficient amount of a granular detergent composition for each wash. Such products also offer considerable convenience to those consumers who launder the clothes outside or away from their residence (e.g. at a laundromat) because the consumer is required to transport only precisely as much laundry detergent as needed for clothes laundering.
However, while detergent compositions in tablet form have a number of advantages over conventional granular laundry detergent products, there are also disadvantages in using them. In particular, detergent tablets can be very “friable”, meaning that they are weak and may easily break apart into smaller pieces during manufacture, transportation and storage. Such product integrity degradation is not only immediately undesirable to a consumer from an aesthetics standpoint, but also eliminates many of the advantages that detergent compositions in a tablet form have over conventional granular products. Given the foregoing, there is a continuing need to provide detergent tablets which are strong and durable and can withstand the agitation and disturbances, which are incidental to their manufacture, transportation and storage.
There are several approaches for enhancing the strength and durability of tablet detergent compositions, including packing the constituent particles which form the tablets more tightly by compacting them at higher compacting pressures and including a binder which provides a cohesive effect on the tablets. However, while these approaches may provide a stronger detergent tablet they may also introduce another disadvantage to detergent tablets. Because of their compact nature there is less surface area immediately in contact with the wash water and therefore, they dissolve more slowly. The inhibited disintegration of the tablets when contacted with the wash liquor during use limits the availability of functional detersive benefits that can be provided. Slow dissolving tablets have the additional disadvantage in that they can deposit visible detergent residues on clothes.
Accordingly the need remains for detergent tablets which are both strong and durable to resist breakage during storage and transportation, but which also disintegrate rapidly upon contact with wash water so that the components of the tablet can provide detersive benefits during the wash process.
The present invention meets the aforementioned needs by providing a detergent composition in tablet form comprising an improved solubility aid, which also functions as a binder. The resulting tablets are of a low friability and can thus be stored and transported easily without breakage, and also disintegrate rapidly during the wash processes conducted using either semi-automatic, automatic or hand washing machines.
It has now been discovered that certain solubility aids also provide benefits as binding agents and that the addition of these solubility aids to a particulate detergent composition which is subsequently formed into a tablet provides a strong, durable tablet with excellent disintegration and dissolution properties so that the detersive benefits of the tablet components are available for nearly the entire length of the wash process. Additionally, less detergent residue is deposited on fabrics laundered with said tablets.